/*
 * Copyright (c) 2007 Vreixo Formoso
 * 
 * This file is part of the libisofs project; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License version 2 as 
 * published by the Free Software Foundation. See COPYING file for details.
 */

#ifndef LIBISO_UTIL_H_
#define LIBISO_UTIL_H_

#include <stdint.h>
#include <time.h>

#ifndef MAX
#   define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif

#ifndef MIN
#   define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif

extern inline int div_up(unsigned int n, unsigned int div)
{
    return (n + div - 1) / div;
}

extern inline int round_up(unsigned int n, unsigned int mul)
{
    return div_up(n, mul) * mul;
}

int int_pow(int base, int power);

/**
 * Convert a given string from any input charset to ASCII
 * 
 * @param icharset
 *      Input charset. Must be supported by iconv
 * @param input
 *      Input string
 * @param ouput
 *      Location where the pointer to the ouput string will be stored
 * @return
 *      1 on success, < 0 on error
 */
int str2ascii(const char *icharset, const char *input, char **output);

/**
 * Ensure a given string is a valid ISO directory identifier, modifying
 * it if needed.
 * 
 * @param src
 *      The identifier, in ASCII encoding. It may be modified by the function.
 * @param maxlen
 *      Maximum length supported by current iso level.
 */
void iso_dirid(char *src, int maxlen);

/**
 * Ensure a given string is a valid ISO level 1 file identifier, in 8.3 
 * format, modifying it if needed.
 * Note that version number is not added to the file name
 * 
 * @param src
 *      The identifier, in ASCII encoding. It may be modified by the function.
 */
void iso_1_fileid(char *src);

/**
 * Ensure a given string is a valid ISO level 2 file identifier, modifying it
 * if needed.
 * Note that version number is not added to the file name
 * 
 * @param src
 *      The identifier, in ASCII encoding. It may be modified by the function.
 */
void iso_2_fileid(char *src);

/**
 * Convert a given input string to d-chars.
 * @return
 *      1 on succes, < 0 error, 0 if input was null (output is set to null)
 */
int str2d_char(const char *icharset, const char *input, char **output);
int str2a_char(const char *icharset, const char *input, char **output);

void iso_lsb(uint8_t *buf, uint32_t num, int bytes);
void iso_msb(uint8_t *buf, uint32_t num, int bytes);
void iso_bb(uint8_t *buf, uint32_t num, int bytes);

/** Records the date/time into a 7 byte buffer (ECMA-119, 9.1.5) */
void iso_datetime_7(uint8_t *buf, time_t t);

/** Records the date/time into a 17 byte buffer (ECMA-119, 8.4.26.1) */
void iso_datetime_17(uint8_t *buf, time_t t);

typedef struct iso_rbtree IsoRBTree;

/**
 * Create a new binary tree. libisofs binary trees allow you to add any data
 * passing it as a pointer. You must provide a function suitable for compare
 * two elements.
 *
 * @param compare
 *     A function to compare two elements. It takes a pointer to both elements
 *     and return 0, -1 or 1 if the first element is equal, less or greater 
 *     than the second one.
 * @param tree
 *     Location where the tree structure will be stored.
 */
int iso_rbtree_new(int (*compare)(const void*, const void*), IsoRBTree **tree);

/**
 * Destroy a given tree.
 * 
 * Note that only the structure itself is deleted. To delete the elements, you
 * should provide a valid free_data function. It will be called for each 
 * element of the tree, so you can use it to free any related data.
 */
void iso_rbtree_destroy(IsoRBTree *tree, void (*free_data)(void *));

/**
 * Inserts a given element in a Red-Black tree.
 *
 * @param tree
 *     the tree where to insert
 * @param data
 *     element to be inserted on the tree. It can't be NULL
 * @param item
 *     if not NULL, it will point to a location where the tree element ptr 
 *     will be stored. If data was inserted, *item == data. If data was
 *     already on the tree, *item points to the previously inserted object
 *     that is equal to data.
 * @return
 *     1 success, 0 element already inserted, < 0 error
 */
int iso_rbtree_insert(IsoRBTree *tree, void *data, void **item);

/**
 * Get the number of elements in a given tree.
 */
size_t iso_rbtree_get_size(IsoRBTree *tree);

/**
 * Get an array view of the elements of the tree.
 * 
 * @return
 *    A sorted array with the contents of the tree, or NULL if there is not
 *    enought memory to allocate the array. You should free(3) the array when
 *    no more needed. Note that the array is NULL-terminated, and thus it
 *    has size + 1 length.
 */
void **iso_rbtree_to_array(IsoRBTree *tree);

#endif /*LIBISO_UTIL_H_*/